高性能桥梁钢典型焊接接头疲劳性能试验研究

针对Q500qE高性能钢两种典型焊接接头，包括对接焊缝和横向角接焊缝，设计疲劳试件。其中对接焊试件包括两种形式，分别为板厚56mm和8mm的对 接焊试件；横向角接焊缝试件的主板厚56mm、附连件厚20mm。对三组试件进行了有限元分析，掌握了试件的应力分布状况及薄弱环节，验证了试件设计的合 理性。随后针对三组试件展开了疲劳试验，掌握了不同类型焊接接头的破坏位置及破坏形式。根据试验结果拟合出了三组试件的S-N曲线，并与普通钢的疲 劳性能进行比较，表明Q500qE高性能钢的这两种典型焊接接头的疲劳强度略高于普通钢。采用目前规范规定的疲劳强度容许值进行抗疲劳设计是合理可行的，并且具有足够的安全余量。

Experimental study on fatigue performance of typical welded joints of high performance steel

The fatigue performances of two typical welded joints of Q500qE high performance steel including butt weld and transverse fillet weld are studied. First, the fatigue specimens of butt weld and transverse fillet weld are designed respectively. The butt weld specimens include two thickness, one is 56mm-thick and the other is 8mm-thick. The board thickness of the transverse fillet weld specimen is 56mm, and the attachment is 20mm thick. Then the finite element models of  specimens are constructed, by which the stress distribution and the weak position are analyzed, and the design rationality of the specimens is verified. Finally, the fatigue experiments are carried out to analyze the failure positions and failure forms of different welded joints. The S-N curves of three groups of specimens are obtained and compared with ordinary steel welded joints. The analysis results show that the fatigue strength of two welded joints with Q500qE is slightly higher than that of ordinary steel. According to current specifications, the allowable values of fatigue strength used for design of Q500qE weld joints are safe, reasonable and feasible.